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What would be stronger, in this loading configuration, the 2x4 or two 3-1/2" wide strips of 3/4" plywood glued together into a 2x4?

View attachment 449448
Depending on the grade of plywood and gluing method, the plywood obviously. Micro lams are regularly used in framing where dimensional lumber can not meet the load requirement. Micro lams are nothing but dimensional lumber sized veneer plywood.
 

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Discussion Starter · #25 ·
It's a funny clip.
Last week I let my dog outta the shop at night to go pee.

As soon as I opened the door, there was a rabbit about ten feet away, and my dog chased it.

The dog cornered the rabbit, and the rabbit actually attacked the dog.

Dog had a little scratch on the bridge of his nose.

The dog's immediate reaction was to run away.

It reminded me of this part.

 

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Depending on the grade of plywood and gluing method, the plywood obviously. Micro lams are regularly used in framing where dimensional lumber can not meet the load requirement. Micro lams are nothing but dimensional lumber sized veneer plywood.
But, Micro lams are different from a sheet of plywood in that the engineered beam has all of the grain of the wood running the same direction. The plywood has alternating layers at right angles to each other. With that in mind the 2x4 in the original photo might be stronger.
 

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You can run a roundover on plywood. The only issue is it put additional wear on the router bit and will actually wear a groove in the bit where the glue line is.

Not sure why you are having an issue with the forstner bit. If you are using a hand drill they are more difficult to control and perhaps you let the bit wobble a bit. A forstner bit is better used on a drill press. Then the forstner bit will drill a cleaner hole such as a brad point bit. A twist drill may be drilling slightly undersize.

A stud will probably remain straight but be twisted a little. Being wood though there is no set rules. Sometimes the wood has a mind of it's own. If the wall is critical to be true and straight it's better not to use a bad board to be sure.

Wood glue functions by soaking into the grain of the wood and turns to a plastic. If the wood is sealed with linseed oil or anything it won't work. Even just wood stain would reduce the effectiveness of the glue.

The strength of a 2x4 would be stronger than plywood glued together, especially if the 2x4 was southern pine. In addition, plywood is likely someday to delaminate. You don't want to frame with a material which in 30 years may come apart.
 

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Measure the forster bit and twist bit with a caliper. It's possible it's oversized. Or... the dowel is undersized. On top of that wobble in the drill press spindle might make the hole larger, but sounds unlikely because of the way the forstner bit is designed.
 

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Discussion Starter · #31 ·
Not all dowels are created equal. I would expect that the forstner bit is accurate unless it is a real cheapo.
Harbor Freight.

But they mic dead on balls accurate.

Methinks it's the low RPM.

My drill press chuck has a slight wobble at low RPM ever since my dad launched an unclamped piece of plywood across the shop with a fly cutter about ten years ago.
 

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Discussion Starter · #32 ·
Is it possible to put a roundover edge on plywood using a router, or will it tear it up?
My first question is resolved. I made these with a 3/4" dome shaped bit. There's no purpose for these items. I was just experimenting, learning. The shellac finishes are another experiment to see if plywood can be made pretty, and I guess I'm also going to see how shellac holds up to skin oil and light friction. Wifey likes to run her fingers back and forth through the router cuts like one of those soapstone blocks with the spoon shaped concavity you're supposed to rub with your thumb.

Wood Cuisine Hardwood Varnish Wood stain

Wood Rectangle Dishware Wood stain Tableware
 

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Discussion Starter · #36 ·
Wood Automotive tire Oreo Hardwood Auto part


The center part of this pulley is two pieces of oak, glued up with their grain directions perpendicular.

I'd like to use that router bit to round out the groove in the pulley where the rope will go.
Its not necessary but it'll look better.
 

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Discussion Starter · #39 ·
The router bit wouldn't know the difference except if you route wood that is glued up like plywood very much it will quickly dull the bit. The glue line is very abrasive on even carbide tip bits.
Maybe I can just chuck up that bolt in the drill press and spin it while holding a rat tail file in it.

I already spun it in the drill press but I had it at 200 RPM and I was just holding sandpaper on it.
 
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